The Klippel-Feil syndrome is an autosomal dominant disorder defined as congenital fusion of two or more cervical vertebra. The classic clinical triad of short neck, low hair line, and restricted neck motion is present in less than 50% of patients with this syndrome. This disorder results from failure of normal segmentation of the somites during the 3rd to 8th week of gestation. Three types of Klippel-Feil syndrome have been described: type 1, cervical spine fusion in which elements of many vertebra are incorporated into a single block; type 2, cervical spine fusion in which there is failure of complete segmentation at only one or two cervical levels and may include an occipito-atlantal fusion; and type 3, both cervical fusion and lower thoracic or lumbar fusion with co-existing segmentation errors in the lower dorsal or lumbar spine. Deafness is a common associated feature and may be of sensorineural, conductive, or mixed type, and with a slight excess of females (M:F ratio 1:1.5).
Mutations in GDF6 gene is associated with Klippel-Feil syndrome.
Al Talabani et al. (1998) studied the pattern of major congenital malformations in 24,233 consecutive live and stillbirth at Corniche hospital, which is the only maternity hospital in Abu Dhabi, between January 1992 and January 1995. A total of 401 babies (16.6/1,000), including 289 Arabs, were seen with major malformation. Sporadic conditions accounted for 26% of the cases. In their study, Al Talabani et al. (1998) observed one case of Klippel-Feil syndrome. Recurrence was not reported in other members of the family. Al Talabani et al. (1998) concluded that their study was very close to representing the true incidence of congenital abnormalities in the whole United Arab Emirates, as they investigated over 98% of deliveries in Abu Dhabi, the capital of United Arab Emirates.